Triaxial snubber assembly

ABSTRACT

A method and system for mitigating undesirable motion of the optics of a camera are disclosed. The system can include a stage and snubber assembly for defining motion of the camera optics. The stage and snubber assembly can include a stage assembly having a stage to which the optics are attachable, at least one wing formed upon the stage, and a snubber assembly configured to cooperate with the wing(s) so as to limit motion of the stage substantially to the desired direction of travel of the camera optics.

RELATED APPLICATIONS

This patent application is a continuation-in-part (CIP) patentapplication of U.S. patent application Ser. No. 11/268,849, filed Nov.8, 2005, and entitled CAMERA SNUBBER ASSEMBLY, now U.S. Pat. No.7,646,969, issued Jan. 12, 2010, the entire contents of which are herebyexpressly incorporated by reference. U.S. patent application Ser. No.11/268,849 claims the benefit of the priority date of U.S. provisionalpatent application Ser. No. 60/657,261, filed on Feb. 28, 2005 andentitled AUTOFOCUS CAMERA pursuant to 35 USC 119, the entire contents ofwhich are hereby expressly incorporated by reference.

TECHNICAL FIELD

The present invention relates generally to cameras. The presentinvention relates more particularly to a snubber assembly for limitingthe motion of optical elements in a miniature camera, such as aminiature camera that is suitable for use in a cellular telephone.

BACKGROUND

Miniature cameras are well known. Miniature cameras are widely used incontemporary cellular telephones. They are also used in other devices,such as laptop computers and personal digital assistants (PDAs).Miniature cameras can even be used as stand alone devices for suchapplications as security and surveillance.

Contemporary miniature cameras, such as those used in cellulartelephones, are fixed focus cameras. That is, the focus of the camerasis preset. The camera has a small enough aperture so as to providesufficient depth of field such that focus is generally acceptable over awide range of distances. However, such stopping down of the cameraseverely limits it's use in low light conditions.

Stopping down also limits resolution since it tends to inhibit the useof higher pixel count imagers. As those skilled in the art willappreciate, larger apertures allow higher imager pixel counts, butrequire the use of variable focus.

Variable focus necessitates the use of movable optics. However, movableoptics suffer from inherent disadvantages. Foremost among thesedisadvantages is the size of the mechanisms required to effect andcontrol movement of the movable optics. For example, the structures usedto control the movement of optics in larger cameras are simply too largefor use in many miniature cameras. As such, it is desirable to provideminiature structures for controlling motion in miniature cameras.

BRIEF SUMMARY

A method and system for controlling, i.e., limiting, the motion ofminiature components, such as the optics of a camera, are disclosed. Thesystem can comprise a stage and a snubber assembly for controlling themotion of the stage in six degrees of freedom. Camera optics can beattached to the stage to facilitate focusing and/or zooming. Accordingto one embodiment of the present invention, the stage can move freely inone degree of freedom within a limited range of motion. Thus, themovement of the stage can be used for moving optics so as to effectfocus and/or zoom, for example.

For example, the snubber assembly can readily permit movement in onetranslational degree of freedom while substantially limiting motion inthe other five degrees of freedom. This is accomplished in a manner thatfacilitates focusing and/or zooming of a camera while inhibitingmisalignment of the optics and while also providing some protectionagainst shock and vibration.

Such motion control can be achieved while mitigating the costsassociated with precision manufacturing of the snubber assembly. Moreparticularly, the precision with which manufacturing of the snubberassembly is performed can be reduced by relying upon physical featuresof a stage assembly to facilitate precise positioning of physicalfeatures of the snubber assembly. That is, positioning of at least somefeatures of the snubber assembly are dependent upon correspondingfeatures of the stage assembly such that desirable alignment of thesnubber assembly with respect to the stage assembly results.

According to one embodiment of the present invention, mesas of thesnubber assembly abut stationary or fixed portions of the stage assemblyso as to define, at least in part, one or more horizontal gaps betweenthe stage and the snubber assembly. The size of these horizontal gapsdetermines the limits of horizontal movement of the stage.

Similarly, shims of the snubber assembly abut the fixed portion of thestage assembly so as to define, at least in part, one or more verticalgaps between the stage and the snubber assembly. The size of thesevertical gaps determines the limits of vertical movement of the stage.

Undesirable rotations of the stages can also be limited by the snubberassembly of the present invention. Pitching motion (rotation about thehorizontal or lateral axis, which is orthogonal to the direction oftravel) results in up and down vertical motion of the front and backends of the stage. Similarly, yaw motion (rotation about a verticalaxis) results in horizontal or lateral motion of the front and back endsof the stage. Similarly, roll motion (rotation about an axis along thedirection of travel) results in vertical motion of the sides of thestage. Since the snubber assembly inhibits vertical motion of the frontand back ends of the stage, lateral motion of the front and back ends ofthe stage, and vertical motion of the sides of the stage, these threerotations are substantially inhibited.

According to one aspect of the present invention, smaller features ofthe snubber assembly are manufactured with higher tolerances, whilelarger features of the snubber assembly can be manufactured with lowertolerances. It is not necessary to manufacture larger features of thesnubber assembly with higher tolerances and thus manufacturing costs aretherefore substantially reduced.

According to one embodiment of the present invention, a system forcontrolling motion, such as the motion of camera optics, comprises astage having at least one wing formed thereon and a snubber assemblyhaving a plurality of mesas formed thereon. The mesas can be configuredsuch that they cooperate with the wing(s) so as to control motion of thestage.

More particularly, a stage and snubber assembly for defining motion ofminiature camera optics can comprise a stage assembly comprising a stageto which the optics are attachable, at least one wing formed upon thestage, and a snubber assembly configured to cooperate with the wing(s)so as to limit motion of the stage in five degrees of freedom whilefacilitating a substantially greater amount of motion in a sixth degreeof freedom.

The stage can be configured to move in a generally linear fashion so asto effect focusing of the camera. The wing(s) can be formed upon each oftwo opposing sides of the stage. The wing(s) can be formed upon each oftwo opposing sides of the stage such that the wing(s) extend in adirection that is generally perpendicular to the direction of travel ofthe stage.

The snubber assembly can comprise a plurality of mesas that areconfigured to cooperate with the wing(s) so as to limit movement of thestage. The snubber assembly can comprise two portions, e.g., an upperportion and a lower portion, that are configured to capture the stageassembly therebetween. Each of the two portions can comprise two mesasthat are configured to cooperate with the wing(s) so as to limitmovement of the stage.

More particularly, the snubber assembly can comprise two substantiallyidentical portions that are configured to capture the stage assemblytherebetween. Each of the two portions can comprise two mesas.

The snubber assembly can comprise a plurality of mesas. For example, thesnubber assembly can comprise two, four, six, or eight mesas. Indeed,the snubber assembly can comprise any desired number of mesas. The mesascan be either formed separately from the snubber assembly of can beformed integrally therewith. Each of the two portions of the snubberassembly can comprise two mesas formed integrally therewith.

The two portions of the snubber assembly and the mesas comprise aresilient material. For example, the mesas (as well as the rest of thesnubber assemblies) can comprise a material that is softer and/or moreresilient than a material of which the stage assembly is constructed.More particularly, the mesas (as well as the rest of the snubberassemblies) can comprise a material that is more resilient than thematerial of which the wing(s) are constructed. For example, the mesas(as well as the rest of the snubber assemblies) can comprise a polymermaterial.

The mesas can be configured to abut the wing(s) so as to limit movementof a stage of the stage assembly. The mesas can be configured to abutthe wing(s) when the stage moves more than a predetermined distance inits direction of travel. The mesas can be configured to abut a portionof the stage other than the wing(s) when the stage moves transverselymore than a predetermined distance. The snubber assembly can capture aportion of the stage such that the stage abuts the snubber assembly whenthe stage moves axially more than a predetermined distance.

According to an exemplary embodiment of the present invention, a camera,such as a camera of a cellular telephone or another personal electronicdevice, comprises a stage and snubber assembly for defining motion ofminiature camera optics. The stage and snubber assembly can comprise astage assembly comprising a stage to which the optics are attachable andcan also comprise at least one wing.

According to an exemplary embodiment of the present invention, a methodfor controlling motion of camera optics comprises abutting mesas of asnubber assembly with wings of a stage when the stage moves more than apredetermined distance in its direction of travel, abutting the mesas ofthe snubber assembly with portions of the stage other than the wingswhen the stage moves transversely more than a predetermined distance,and abutting the snubber assembly with the wings when the stage moves upor down more than a predetermined distance.

This invention will be more fully understood in conjunction with thefollowing detailed description taken together with the followingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective top view of a stage and snubber assembly accordingto an exemplary embodiment of the present invention;

FIG. 2 is a top perspective cross-sectional view of the stage andsnubber assembly taken along line 2 of FIG. 1;

FIG. 3 is an outboard perspective view of a snubber portion of FIG. 1;

FIG. 4 is an inboard perspective view of the snubber portion of FIG. 3;

FIG. 5 is a top or bottom (both are identical) perspective view of thestage assembly of FIG. 1;

FIG. 6 is an enlarged fragmentary view of the interface of the topsnubber, the bottom snubber, and the stage, taken within line 5 of FIG.2;

FIG. 7 is a top perspective view of a stage and snubber assemblyaccording to another exemplary embodiment of the present invention; and

FIG. 8 is a top view of the stage assembly of FIG. 7, showing two mesasof a snubber assembly positioned with respect thereto.

Embodiments of the present invention and their advantages are bestunderstood by referring to the detailed description that follows. Itshould be appreciated that like reference numerals are used to identifylike elements illustrated in one or more of the figures.

DETAILED DESCRIPTION OF THE INVENTION

A method and system for defining the motion of a stage is disclosed. Thestage is suitable for mounting camera optics upon. For example, focusand/or zoom lenses can be mounted to the stage. According to one aspectof the present invention, motion of the stage in six degrees of freedomis controlled. More particularly, motion in five degrees of freedom issubstantially limited, while motion in one translational degree isfreedom is facilitated. For example, translational motion in two degreesof freedom can be limited to approximately 10 microns, rotational motionin three degrees of freedom can be limited to approximately 0.1 degrees,and translational motion in one degree of freedom in excess of onemillimeter can be facilitated.

In this manner, the stage can be permitted to translate along one axissufficiently so as to effect focusing and/or zooming, while not beingpermitted to translate sufficiently along other axes or to rotate aboutany axis sufficiently so as to effect misalignment of the optics to adegree that would substantially degrade performance of the camera.Moreover, the snubber assembly of the present invention can beconfigured so as to only effect motion control when the stage is causedto move outside of a set of predefined ranges. That is, the snubberassembly can be configured such that it has no effect until the stageexperiences a shock or abnormal operation that would otherwise cause itto move in an undesirable manner. When this happens, the snubberassembly can then restrict motion of the stage to within the desiredranges, so as to prevent the misalignment of optics, for example. Thus,during normal operation, the snubber assembly can have little or noeffect.

One way to make a snubber assembly that limits movement of a stage is touse close (precise) tolerances to assure that all features of thesnubber assembly are properly located. However, such construction of thesnubber assembly requires that the comparatively large structuresthereof be manufactured with the same close tolerances as thecomparatively small structures. As those skilled in the art willappreciate, while it is comparatively easy to manufacture smallerstructures with such close tolerances, it becomes increasingly difficultto do so as the size of the structures increases. That is, deviationsfrom desired dimensions tend to accumulate across larger distances,making it difficult to maintain close tolerances. According to oneaspect of the present invention, a different approach results in asnubber that precisely limits the motion of a stage.

According to one aspect of the present invention, critical gapdimensions are obtained by manufacturing only selected small structuresof the snubber assembly with comparatively higher precision, whilemanufacturing the rest (particularly the larger dimensions) of thesnubber assembly with substantially lower precision. Because the largerdimensions are manufactured with lower precision, the positions of thesmaller structures of the snubber assembly are not precise.

This lack of precision in the location of the smaller structures can becompensated for by using portions of the stage assembly to preciselyposition the smaller structures. That is, the smaller structures of thesnubber assembly are effectively keyed into position using preciselyformed portions of the stage assembly. Thus, the position of snubbersmanufactured, at least in part, with a comparatively low amount ofprecision is determined by a portion of a stage assembly that ismanufactured with a comparatively high amount of precision.

Referring now to FIGS. 1 and 2, a stage assembly 10 (better shown inFIG. 5) is sandwiched between two portions, 11 and 12 (better shown inFIGS. 3 and 4), of a snubber assembly 13, according to one embodiment ofthe present invention. The stage assembly 10 and the snubber assembly 13can be generally planar structures, formed from silicon, for instance.Stage assembly 10 and/or snubber assembly 13 can alternatively be formedfrom another material, such as plastic or metal. Alternatively, both thestage assembly 10 and the snubber assembly 13 can be formed from eitherplastic or silicon or any other desired material or combination ofmaterials.

Stage assembly 10 comprises a stage 41 that moves back-and-forth, so asto facilitate movement of optics for focusing and/or zooming, forexample. Stage assembly 10 further comprises a frame 42 that generallysurrounds stage 41 (as best seen in FIG. 5). Frame 42 is fixed inposition with respect to snubber assembly 13 and thus does not move.Arrow 16 shows the back-and-forth directions of motion of stage 41 withrespect to frame 42 (better shown in FIG. 5) and with respect to snubberassembly 13. Snubber assembly 13 facilitates such back-and-forth motionof stage 41 while substantially inhibiting all other motions of stage41.

Referring now to FIGS. 3 and 4, each portion 11, 12 of snubber assembly13 can be a generally planar and generally rectangular structure.Snubber assembly 13 can comprise two biasing members 31 and 32 thatfunction as springs to bias two sides 33 and 34 outwardly, so as tocause them to contact portions (surfaces 56 and 57 as shown in FIG. 6)of frame 42 in a manner that advantageously positions critical featuresof snubber assembly 13, as discussed in detail below. Alternatively, theinherent resiliency of snubber assembly 13 can effect such biasing.

Each biasing member 31, 32 can comprise an inboard member 35, anoutboard member 36, and two side members 37 and 38 that are configure tocooperate so as to provide spring tension that moves the sides 33 and 34outwardly after sides 33, 34 have been pushed inwardly (such as whenstage assembly 10 is being installed therebetween). That is, therectangle defined by an inboard member 35, an outboard member 36, andtwo side members 37 and 38 can deform so as to define a parallelogramthat provides spring tension. Each portion 11, 12 of snubber assembly 13further comprises structural features that cooperate with stage assembly10 to define tolerances or spacings between snubber assembly 13 andstage 41, as discussed in detail with reference to FIG. 6 below.

With particular reference to FIG. 4, each portion 11, 12 of snubberassembly 13 may have formed upon an inboard (snubber assembly 10contacting) surface thereof a plurality of mesas 51, shims 61, and stops58, the functions of which are discussed in detail with reference toFIG. 6 below. Although mesas are shown formed upon both of the snubberassemblies, mesas may alternatively be formed upon only one of thesnubber assemblies. Mesas can be formed upon both snubber assemblies soas to maintain symmetry (so as to allow a single part to be capable ofbeing used as either an upper snubber or a lower snubber. However, suchsymmetry is not a requirement. Therefore, a single mesa (which willgenerally have approximately twice the height of the mesas shown in FIG.4) can replace each complimentary pair of mesas.

Referring now to FIG. 5, stage assembly 10 comprises a movable portionor stage 41 and a fixed portion or frame 42. Stage 41 can be a generallyplanar, generally rectangular structure. Optics are attachable, eitherdirectly or indirectly, to stage 41.

Stage 41 can move in response to a motor or actuator, such as to effectfocusing and/or zooming. For example, an optics assembly (not shown) canbe attached to stage 41 via apertures 43 a-43 d.

Frame 42 can similarly be a generally planar and generally rectangularstructure that can substantially surround a periphery of stage 41. Frame42 can be movably attached to stage 41 via flexure assemblies 45 and 46.Flexure assemblies 45 and 46 can preferentially facilitate movement ofstage 41 in one desired translational degree of freedom, i.e., in theback-and-forth directions of arrow 16 of FIG. 1. Snubber assembly 13 canlimit movement of stage 41 that is beyond the one desired translationdegree of freedom.

Stage 41, as well as frame 42, snubber assembly 13, and other componentsof the present invention, can be of any desired shape and/orconfiguration. Stage assembly 10 can be formed monolithicly, such as viathe etching or milling of a single piece of silicon or other material.Similarly, snubber assembly 13 can also be formed monolithicly.Alternatively, stage assembly 10 and/or snubber assembly 13 can beformed in any other desired manner using any desired material. Indeed,the reduced precision needed by snubber assembly 13 according to oneaspect of the present invention allows snubber assembly 13 to be formedof plastic using low a precision manufacturing process.

Snubber assembly 13 defines limits to movement of stage 41, so as toinhibit movement in five other degrees of freedom for which it isdesirable to restrict movement of stage 41. Such limitations on themovement of stage 41 tend to maintain desired alignment of components,such as optics. The limitations are also desirable, for example, in theevent of shock or vibration that would other cause stage 41 to move in amanner that may cause damage to itself or other components, e.g., lensesof a camera. Thus, the stage, and consequently the camera optics, can bepermitted to move in a manner that facilitates desired functionality,e.g., focusing and/or zooming, while also being restrained in a mannerthat mitigates undesirable malfunctioning (misalignment of optics) anddamage.

Referring now to FIG. 6, exemplary structures of stage assembly 10 andsnubber assembly 13 that limit motion of stage 41 in five degrees offreedom while facilitating substantially more motion in a sixth degreeof freedom (as indicated by arrow 16 in FIG. 1) are shown. Each portion11, 12 of snubber assembly 13 comprises features such as mesas 51, 52,shims 53, 54, and stops 58, 59 that define limits to the movement ofstage 41 in five degrees of freedom while permitting unrestrictedmovement of stage 41 in one degree of freedom.

Mesas 51, 52, shims 53, 54, and stops 58, 59 are formed precisely. Theyare also precisely positioned by keying to or abutting precisely formedportions of frame 42, so that they are, in-turn, precisely positionedthemselves and are thus suitable for defining limits to the movement ofstage 41.

In this manner, the limits to the movement of stage 41 can be definedwith greater precision than the precision with which the overall snubberassembly 13 is manufactured because the snubber assembly 13 cooperateswith the frame 42 of the stage assembly 10 to define positioning of thestructures that limit motion of stage 41 and because frame 42 ismanufactured with sufficient precision so as to facilitate suchdefinition of these positions.

More particularly, the width, Dimension A, of each mesa 51, 52 togetherwith the distance between stage 41 and frame 42, Dimension C, definesthe size of the horizontal gap, Dimension B, between stage 41 andsnubber assembly 13. Since the width of each mesa 51, 52, Dimension A,and the distance between the stage 41 and the frame 42, Dimension C, canbe easily controlled, the horizontal gap, Dimension B, can likewise beeasily controlled. The distance between the stage 41 and frame 42,Dimension C, is controlled by precisely manufacturing the overalldimensions of stage assembly 10. The width of mesa 51, 52 only requiresprecision in the manufacturing of a comparatively small portion of thesnubber assembly 13, i.e., each mesa 51, 52 itself. It does not requirethat the position of each mesa 51, 52 be precisely determined duringmanufacturing of snubber assembly 13.

Positioning of each mesa 51, 52 is determined by its contact with frame42 at surfaces 56 and 57. Contact at surfaces 56 and 57 is effected bythe outward biasing of side members 33 and 34 of each portion 11, 12 ofsnubber assembly, as described above. Since frame 42 of snubber assembly13 is manufactured with precision, this contact point is preciselylocated. Thus, the size of the horizontal gap, Dimension B, between thestage 41 and the snubber assembly 13 can be controlled without requiringthat the overall manufacturing tolerances of snubber assembly 13 beprecise.

Similarly, the thickness, Dimension D, of each shim 53, 54 together withthe thickness, Dimension E, of frame 42, defines the size of eachhorizontal gap, such as Dimension F, between stage 41 and the stops 58,59 of snubber assembly 13. Shims 53, 54 contact frame 42 at surfaces 61,62 thereof. This contact is effected by attachment of the upper portion11 to the lower portion 12 of snubber assembly 13 by any desired means,such as by adhesive bonding. Upper portion 11 and lower portion 12 canbe attached to one another directly, or can be attached to one anotherindirectly, such as by adhesively bonding upper portion 11 and lowerportion 12 to stage 41 or by using detents or the like to attach upperportion 11 and lower portion 12 to stage 41.

There are two such vertical gaps on each of the two sides of stage 41.On each side of stage 41, one vertical gap is above stage 41 and onevertical gap is below stage 41. Since the thickness, Dimension D, ofeach shim 53, 54, and the thickness, Dimension E, of frame 42 can beprecisely controlled, each vertical gap, Dimension F, can also beprecisely controlled. The thickness, Dimension D, of each shim can becontrolled by precisely manufacturing a small portion of the snubberassembly 13. The thickness, Dimension E, of frame 42 can be preciselycontrolled during manufacture thereof. As with the horizontal gap,Dimension B, the distance between stage 41 and frame 42 defining eachone of the vertical gaps, such as Dimension F, is controlled byprecisely manufacturing the overall dimensions of stage assembly 10. Thethickness, Dimension D, of shims 53, 54 only requires precision in themanufacturing of a comparatively small portion of snubber assembly 13,i.e., each shim 53, 54 itself. Again, it does not require that theposition of each shim 53,54 be precisely determined during manufacturingof snubber assembly 13.

It is worthwhile to note that a vertical gap, Dimension G, is providedbetween mesas 51 and 52 to insure that they do not contact one anotherand thereby interfere with proper positioning of shims 53 and 54 (andconsequently with the definition of the vertical gaps between stage 41and snubber assembly 13, such as Dimension F). The size of the verticalgap, Dimension G, is not crucial.

For example, Dimension A can be approximately 300 microns, Dimension Bcan be approximately 10 microns, Dimension C can be approximately 310microns, Dimension D can be approximately 25 microns, Dimension E can beapproximately 300 microns, Dimension F can be approximately 10 microns,and Dimension G can be approximately 25 microns. However, as thoseskilled in the art will appreciate, various other values for thesedimensions are likewise suitable and the dimensions used will dependupon the specific application.

Thus, only the mesas 51, 52, shims 53, 54 and stops 58, 59 of snubberassembly 13 need be precisely manufactured. These are comparativelysmall portions of snubber assembly 13 and can thus be preciselymanufactured with relative ease. The overall dimensions of snubberassembly 13 do not require such precision. Moreover, according to oneaspect of the present invention, close tolerances (Dimensions B and F,for example) between the stage 41 and the snubber assembly 13 areobtained without requiring that the larger dimensions of snubberassembly be precisely controlled.

Rather, the larger dimensions of stage assembly 10 are controlled, aswell as the smaller dimensions of critical structures of snubberassembly 13 that cooperate with stage assembly 10 to determine thedimensions of critical gaps therebetween (such as Dimensions B and F).In this manner, the manufacturing process of the stage and snubberassembly of the present invention is simplified and the cost thereof ismitigated.

Optionally, channels 63 and 64 are formed in upper 11 and lower 12portions of snubber assembly 13. Channels 63 and 64 mitigate thelikelihood of edges 81 and 82 (FIG. 5) of stage 41 contacting upper 11and lower 12 portions of snubber assembly 13 and causing damage to stage41 and/or snubber assembly 13.

Similarly, cutouts 71-74 (best shown in FIG. 3) can be formed in upper11 and lower 12 portions of snubber assembly 13 to inhibit corners 86-89(FIG. 5) from contacting upper 11 and lower 12 portions of snubberassembly 13 and causing damage to stage 41 and/or snubber assembly 13.

In operation, stage 41 can move substantially in one translationaldegree of freedom, as indicated by arrow 16 of FIG. 1. For example,optics mounted to stage 41 can be moved in these directions to effectfocusing and/or zooming of a camera. Such movement of stage 41 resultsin compression of one set of flexures (such as flexures 45 of FIG. 5),while simultaneously resulting in expansion of the other set of flexures(such as flexures 46 of FIG. 5). The amount of movement along this onedegree of freedom is limited by the configuration of flexures 45, 46 andby the size of frame 42, not by snubber assembly 13.

It is also worthwhile to note that the stage and snubber assembly of thepresent invention can be configured such that during normal operationstage 41 does not contact snubber assembly 13. Thus, the snubbing actionthat can be provided by mesas 51, 52 and stops 58, 59 can be forextraordinary circumstances, such as when the device is accidentallydropped. However, in such extraordinary circumstances, the snubberassembly of the present invention can prevent excessive motion in anycombination of degrees of freedom.

Movement in the five restricted degrees of freedom is comparativelylimited. Translation of stage 41 from side-to-side (toward and away frommesas 51, 52) is limited by mesas 51, 52. That is, when stage 41 movesfrom side-to-side by an amount greater than Dimension B, it contactsmesas 51, 52, which restrict its motion. Translation of stage 41 up anddown (toward and away from stops 58, 59) is similarly limited by stops58, 59. All rotations of stage 41 are limited by either mesas 51, 52 orstops 58, 59.

More particularly, undesirable pitching motion (rotation about thehorizontal or lateral axis, which is orthogonal to the direction oftravel) results in up and down vertical motion of the front and backends of the stage that is limited by stops 58. Similarly, yaw motion(rotation about a vertical axis) results in horizontal or lateral motionof the front and back ends of the stage that is limited by mesas 51.Similarly, roll motion (rotation about an axis along the direction oftravel) results in vertical motion of the sides of the stage that islimited by stops 58. Since snubber assembly 13 inhibits vertical motionof the front and back ends of stage 41, lateral motion of the front andback ends of the stage 41, and vertical motion of the sides of the stage41, these three rotations, i.e., pitch, roll, and yaw, are substantiallyinhibited.

Thus, according to at least one aspect of the present invention, motioncontrol is provided for camera optics or the like wherein limits on themovement of the optics are defined by a snubber assembly that can bemanufactured, at least in part, using comparatively low precisiontechniques. This is because features of fixed portion or frame 42 ofstage assembly 10 are used to align motion limiting features (such asmesas 51, 52 and stops 58, 59) of snubber assembly 13. In this manner,the cost of manufacturing the stage and snubber assembly issubstantially mitigated.

Referring now to FIGS. 7 and 8, exemplary structures of a stage assembly300, an upper snubber assembly 100, and a lower snubber assembly 200 areshown. These exemplary structures limit motion of stage 103 in fivedegrees of freedom while facilitating substantially more motion in asixth degree of freedom, as indicated by arrow 104. Arrow 104 indicatesthe directions of travel of stage 103. That is, arrow 104 indicates thedirections that stage 103 moves so as to effect focusing (or zooming orany other desired optical effect) of a miniature camera.

Stage assembly 300 cooperates with upper snubber assembly 100 and lowersnubber assembly 200 to provide triaxial snubbing. Thus, both lateraland axial snubbing is provided for stage 103 and camera optics mountedthereto.

More particularly, stage 300 is sandwiched or captured between uppersnubber assembly 100 and lower snubber assembly 200. Stage assembly 300is configured to facilitate movement of a lens assembly, such as afocusing or zoom lens assembly, as discussed above. Upper snubberassembly 100 and lower snubber assembly 200 can be identical withrespect to one another.

Both upper snubber assembly 100 and lower snubber assembly 200 comprisemesas 101. Mesas 101 cooperate with potentially abutting structures ofstage 103 to provide both lateral (transverse) and axial snubbing.Snubbing is provided in one lateral axis by mesas 101 and in the otherlater axis by other structures of upper snubber assembly 100 and lowersnubber assembly 200. Thus, snubbing in the two lateral directions (thetwo directions that are orthogonal to arrow 104, as indicated by arrows105 and 109) and snubbing in the axial direction (the direction of arrow104) are provided.

Snubbing in one lateral direction (the transverse or side-to-sidedirection indicated by arrow 105 of FIG. 8) is limited by the snubbingaction of surfaces 106 against mesas 101. That is, when the transversemovement of stage 103 exceeds a predetermined tolerance, as defined bythe distance or gap between surface 106 and mesa 101, then surface 106abuts mesa 101 and thus limits the transverse movement of stage 103.

The up-and-down movement (indicated by arrow 109 of FIG. 7) of wings 107formed on stage 103 (and thus of stage 103 itself) is limited byabutting portion 108 of upper snubber assembly 100 and lower snubberassembly 200. That is, when the up-and-down movement of stage 103exceeds a predetermined tolerance, as defined by the distance or gapbetween surfaces 108 and wings 107, then wings 107 abuts surfaces 108and thus limit the upon-and-down movement of stage 103.

The axial movement (indicated by arrow 104 of FIG. 8) of wings 107formed on stage 103 (and thus of stage 103 itself) is limited byabutting portions 110 of wings 107 and mesas 101. That is, when theaxial movement of stage 103 exceeds a predetermined tolerance, asdefined by the distance or gap between surfaces 110 and mesas 101, thenwings 107 abut mesas 101 and thus limit the axial movement of stage 103.

The stage assembly 103 can be formed of silicon, plastic, or any otherdesired material. The snubber assemblies 100 and 200 can be formed ofsilicon, plastic, or any other desired material. The mesas 101 can beformed integrally with the snubber assemblies. The mesas 106 and/or theentire upper 100 and lower 200 snubber assemblies can be formed of amaterial that is softer and/or more resilient than the material of whichthe stage assembly 300 is formed. For example, the stage assembly 103can be formed of silicon and the snubber assemblies can be formed of apolymer material.

Thus, according to this exemplary embodiment of the present invention,snubbing in three axes is provided in a stage/snubber assembly 400without the need for external structures. Snubbing is provided to thestage 103 prior to the addition of a lens assembly, so as to mitigatethe likelihood of damage to stage assembly 300 during handling andtransportation. That is, overtravel or excessive movement of the stage103 is limited in a manner that mitigates damage to the stage assembly300, as well to any components attached thereto.

Although the snubber assembly is described herein as being suitable forcontrolling the motion of a stage that supports the optics of a camera,those skilled in the art will appreciate that the stage can similarly beused to support other items. For example, the stage can alternatively beused to position a specimen for viewing under a microscope or for otheranalysis. Thus, discussing the invention herein as being useful forpositioning the optics of a camera is by way of example only, and not byway of limitation.

Embodiments described above illustrate, but do not limit, the invention.It should also be understood that numerous modifications and variationsare possible in accordance with the principles of the present invention.Accordingly, the scope of the invention is defined only by the followingclaims.

1. A system for controlling motion, the system comprising: a stagehaving four corners, a generally planar upper surface, front and rearedges resiliently supported for generally rectilinear movement of theupper surface along a motion control axis lying in the plane of theupper surface and perpendicular to the front and rear edges of thestage, and opposite side edges, each having a laterally extending wingformed thereon and defining a cutout at each of the four corners of thestage; and, a snubber assembly surrounding the periphery of the stageand having four mesas formed thereon, each of the mesas extendinggenerally perpendicular to the plane of the upper surface of the stageand into a corresponding one of the cutouts of the stage and beingconfigured to cooperate with adjacent edges of the stage and the wingsso as to limit movement of the upper surface of the stage tosubstantially rectilinear movement along the motion control axis.
 2. Astage and snubber assembly for defining motion of miniature cameraoptics, the stage and snubber assembly comprising: a stage assemblycomprising a stage having four corners, a generally planar upper surfaceto which the optics are attachable, front and rear edges resilientlysupported for generally rectilinear movement of the upper surface alonga motion control axis lying in the plane of the upper surface andperpendicular to the front and rear edges of the stage, and oppositeside edges, each having a laterally extending wing formed thereon anddefining a cutout at each of the four corners of the stage; and, asnubber assembly surrounding the periphery of the stage and having fourmesas formed thereon, each of the mesas extending generallyperpendicular to the plane of the upper surface of the stage and into acorresponding one of the cutouts of the stage and being configured tocooperate with adjacent edges of the stage and the wings so as to limitmovement of the upper surface of the stage to substantially rectilinearmovement along the motion control axis.
 3. The stage and snubberassembly as recited in claim 2, wherein movement of the stage effectsfocusing of the camera.
 4. The stage and snubber assembly as recited inclaim 2, wherein the snubber assembly comprises two portions that areconfigured to sandwich the stage assembly therebetween.
 5. The stage andsnubber assembly as recited in claim 2, wherein the snubber assemblycomprises two portions that are configured to sandwich the stageassembly therebetween and each of the two portions comprises two of themesas.
 6. The stage and snubber assembly as recited in claim 5, whereinthe snubber assembly comprises two substantially identical portions. 7.The stage and snubber assembly as recited in claim 2, wherein the mesasare formed integrally with the snubber assembly.
 8. The stage andsnubber assembly as recited in claim 2, wherein the snubber assemblycomprises two substantially identical portions that are configured tocapture the stage assembly therebetween and each of the two portionscomprises two mesas formed integrally therewith.
 9. The stage andsnubber assembly as recited in claim 2, wherein the snubber assemblycomprises two substantially identical portions that are configured tocapture the stage assembly therebetween, each of the two portionscomprises two mesas formed integrally therewith, and the portions andthe mesas comprise a resilient material.
 10. The stage and snubberassembly as recited in claim 2, wherein the snubber assembly comprisestwo substantially identical portions that are configured to capture thestage assembly therebetween, each of the two portions comprises twomesas formed integrally therewith, and the portions and the mesascomprise a material that is softer than a material of the stageassembly.
 11. The stage and snubber assembly as recited in claim 2,wherein the snubber assembly comprises two substantially identicalportions that are configured to capture the stage assembly therebetween,each of the two portions comprises two mesas formed integrallytherewith, and the portions and the mesas comprise a material that ismore resilient than a material of the wing(s).
 12. The stage and snubberassembly as recited in claim 2, wherein the snubber assembly comprisestwo substantially identical portions that are configured to capture thestage assembly therebetween, each of the two portions comprises twomesas formed integrally therewith, and the portions and the mesascomprise a polymer material.
 13. A camera, comprising the stage andsnubber assembly as recited in claim
 2. 14. A cellular telephone,comprising the camera as recited in claim 13.